exit 1 if any tests failed
add travis file
sort list of conf files
detect runtime errors in selfcheck, suggested by @job
correct icmp timestamp (request) and nearby cosmetics

Addressing self-note in lib/exabgp/protocol/ip/icmp.py line 23.
correct typos and standardize return message for unknown protocol elements
Merge pull request #193 from wk/timestamp

correct icmp timestamp (request) and nearby cosmetics
Merge pull request #192 from PowerDNS/travis

Add travis-ci testing